Ultrasound imaging system

Abstract

An ultrasound imaging system particularly adapted for detecting structure which reflects ultrasound at a variety of angles. There is a plurality of ultrasound transducers, which may be a linear array or a two-dimension array with the various horizontal rows of the array offset from one another, but having zero horizontal space or overlapping between adjacent vertical transducers. A sequencer causes one transducer to fire and then listen for an echo; if no echo is heard, the same transducer fires again and an adjacent transducer listens; if there is still no echo, the transducer fires and the next adjacent transducer listens; and so on until a predetermined listening sequence is concluded. If an echo is heard at any time, the listening sequence is terminated and the next transducer fires, as determined by a predetermined firing sequence, and the listening sequence for that firing transducer is conducted until an echo is heard or the listening sequence is completed; and so on until the firing sequence is completed. A counter measures the time between the transducer firing and the receipt of the echo to produce a range signal representative of the distance from the transducer face to the structure producing the echo. The signals produced by the transducers upon receipt of the echo and the range signal are processed by computer to produce a visual representation of the structure imaged, such as spine and rib structure.

What is claimed is: 
     
       1. An ultrasound imaging system comprising: a plurality of ultrasound transducers for generating an ultrasound signal, for receiving an ultrasound signal, and for producing a transducer signal representative of said received signal;   means for providing a range signal representative of the distance of object interacting with each ultrasound signal;   timing means for producing a timing signal;   means for energizing said transducers;   means for listening for an ultrasonic wave being received at one of said transducers and for producing a stop signal indicative of each ultrasound wave being received;   sequencing means responsive to said timing signal and electrically connected to said means for energizing and said means for listening for selecting a sequence of firing transducers, for causing said means for energizing to fire a selected firing transducer at first determined time, for selecting a sequence of listening transducers and for causing said means for listening to listen to the listening transducers of the sequence during second determined times, said sequencing means also responsive to said stop signal for selecting the next in the sequence of firing transducers whenever said stop signal is received until said firing and said listening sequences are completed; and   means responsive to said transducer signals and said range signal for producing an output representative of said received ultrasound signals.   
     
     
       2. An ultrasound imaging system as in claim 1 wherein said plurality of transducers is a linear array of transducers and said sequence of listening transducers comprises said firing transducer and one transducer on either side of said firing transducer. 
     
     
       3. An ultrasound imaging system as in claim 1 wherein said plurality of transducers is an N×M two-dimensional array of transducers where N is the number of transducers in each row and M is the number of transducers in each column, and wherein the centers of the transducers in each row are offset from the centers of the transducers in adjacent rows so that lines drawn through the centers of transducers in any row intersect at an angle other than 90° with lines drawn through the centers of transducers in any column. 
     
     
       4. An ultrasound imaging system as in claim 3 wherein said array comprises an N×3 two-dimensional array, the firing transducer is selected from the middle of the three rows, and said sequence of listening transducers comprises said firing transducer and the transducers surrounding each firing transducer. 
     
     
       5. An ultrasound imaging system as in claim 3 wherein, with respect to a rectangular coordinate system in the plane of the array, the edges of each transducer overlap with the edges of neighboring transducers in at least one coordinate direction. 
     
     
       6. An ultrasound imaging system as in claim 3 wherein, with respect to a rectangular coordinate system in the plane of the array, the separation between the edges of neighboring transducers in at least one coordinate direction is zero. 
     
     
       7. An ultrasound imaging system as in claim 1 and further comprising: means for supporting said transducers and for moving said transducers along a determined path; and   means for providing a position signal representative of the position of said transducers with respect to at least one predetermined reference point.   
     
     
       8. An ultrasound imaging system as in claim 7 wherein said means for producing an output comprises a means responsive to said electrical signal, said range signal, and said position signal for identifying signals indicative of the skeletal structure and for producing an output representative of the skeletal structure.